<!DOCTYPE html>
<html lang="en">
<head>
    <meta charset="UTF-8">
    <title>p9_固定定位</title>
  <style>
    .fu {
      background-color:#ff0;
    }
    .fu>div {
      width: 100px;
      height: 100px;
    }
    .z1 {
        background-color: red;
    }
    .z2 {
        background-color: lime;
        position: fixed;
        top: 0;
        right: 0;
    }
    .z3 {
        background-color: blue;
    }
  </style>
</head>
<body>
<div class="fu">
  <div class="z1"></div>
  <div class="z2"></div>
  <div class="z3"></div>
</div>
</body>
</html>